*{
    margin: 0px;
    padding: 0px;
}
.cont{
    width: 1158px;
    height: 253px;
    padding: 50px 0px;
    background-color:#323232;
}
.nav{
    width: 682px;
    height: 76px;
    background-color: white;
    margin: 0px auto;
}
.nav::before{
    content: "";
    border: 38px solid #fff;
    float: left;
    border-left-color: #323232;
}
.nav::after{
    content: "";
    border: 38px solid #fff;
    float: right;
    border-right-color: #323232;
}
li{
    text-align: center;
    width: 120px;
    line-height: 76px;
    float: left;
    list-style: none;
    font-size: 16px;
    height: 76px;
}
.showbox{
    display: none;
    width: 100%;
    height: 10px;
    background-color: #323232;
}
li:hover{
    background-color: #ffd207;
    margin-top: -10px;
}
li:hover .showbox{
    display: block;
}
.showbox::before{
    content: "";
    border: 5px solid #fff;
    float: left;
    border-top-color:  rgba(253, 253, 253, 0.589);
    border-right-color: rgba(253, 253, 253, 0.589);

}
.showbox::after{
    content: "";
    border: 5px solid #fff;
    float: right;
    border-top-color: rgba(253, 253, 253, 0.589);
    border-left-color: rgba(253, 253, 253, 0.589);
}